Jamal Murray is not a star.
Porter and Simons are both lottery level talent with question marks. The questions concerning Simons going into the draft were lack of experience against good competition and the fact that he's skinny. Both of those are easily overcome (Porter has exactly 53 more minutes of college experience than Porter). I know it was summer league, but in his first competition against lottery picks and older players he wasn't overwhelmed either physically or mentally. He held his own. The reason Porter slipped was his injury history. To me, that's a much bigger red flag, especially the nature of his injuries. He has had multiple back and hip injuries. He was walking with a visible limp at his introductory press conference, sat out the summer league and DEN has said they may have him sit out the entire 2018-19 season. Injuries may prevent him from ever living up to his potential. He wouldn't be the first.
Trey Lyles is a decent big off the bench. He can shoot the 3, but he's yet another negative defender. He's going into his fourth season on his second team and has yet to break out. He has shown incremental improvement on offense (his shooting has become more consistent) . He could eventually become a solid, average starter, but I don't see any star potential there. Zach Collins has way more unfulfilled potential. Lyles is 2 years older and while he will likely get incrementally better, I have seen nothing to indicate he's a future star. Collins is all about potential. His rookie year he was physically over matched, but still showed flashes, especially on the defensive end. He has the potential to be above average on both ends of the court. Lyles could be a decent stretch 4 on offense, while getting abused on the other end of the floor. Lyles has nearly 4000 minutes of NBA experience under his belt, but has yet to show that he'll ever be anything more that a solid, average starter. A potential good player? Sure. A star? Highly unlikely.
You, yourself said the best case for the Nuggets was "Plus, in the best-case scenario, they'll have 3 stars in Murray, MPJ, and Jokic". Yet, you completely dismissed our young players. Nurk still has more potential to become a star than anyone one on the Nuggets outside of Jokic (same age). Collins has more untapped potential than Lyles, or any other young DEN big man. I put Simons and Porter at the same level of potential, for different reasons (see above). I'm not sure Trent Jr. has any kind of star potential, but I see a solid role player in the near future and a solid starter eventually.
Yes, our two best players are 28 and almost 27. Both still have several years left before they decline significantly. Damian Lillard has improved every single year he's been in the league. Last year was the first time C.J. did not improve, but that was following two years of astronomical improvement. Neither of these guys are anywhere close to declining. And when they do start to decline, Nurk, Collins, Simons and Trent Jr. will all be entering their primes. We will have a great mix of proven, quality veterans and players in their primes. Who will DEN's veteran leaders be when their young players are entering their prime? No one on their current roster. Millsap and IT will be long gone (it's not like IT is a leader anyway). They may be able to pick up a savvy vet or two, but they won't be getting anyone close to Damian Lillard. DEN isn't GSW, or even HOU. They are no more an attractive free agent destination than Portland.
P.S. I specifically left Wade Baldwin out of the discussion, mostly because he's stuck behind Lillard and McCollum in the rotation, but he's another young Portland player who has the potential to be better than average on both sides of the ball.
BNM